This invention relates to food processors, and more particularly to feedtube protector apparatus for such machines which may be placed on and removed from a large feedtube of a food processor in a single vertical movement of the protector in order to enable or disable the operation of the food processor, permitting easy loading and at the same time protecting the feedtube from inadvertent entry of the user's hand or a foreign object.
Food processors of the type to which the present invention is applicable have a working bowl with motor-driven tool drive means in the bowl on which user-selected rotary food processing tools can be engaged to be driven for performing various food processing operations in accordance with the desires of the user. A detachable cover is secured over the top of the bowl during use which includes a feedtube having a passage that opens downwardly through the cover into the top of the bowl. Food items to be processed are placed in this feedtube and are then manually pushed down through the passage to the rotary tool in the bowl by means of a removable food pusher which is adapted to slide down in the manner of a plunger through the passage in the feedtube.
A bowl cover interlock feature is conventionally provided which requires that the cover be firmly locked on the bowl in normal operating position on the base or housing before the motor drive of the food processor will be enabled to operate. The cover which locks rotationally on the bowl is provided with a projection or actuator which causes the actuation of control means such as a switch carried by the housing only when the cover is properly locked in normal operating position on the bowl. In this arrangement, the motor drive cannot be operated before the cover is properly positioned on the bowl, but the size of the feedtube is restricted in terms of shape, cross-section and height to prevent an adult hand from being inadvertently inserted sufficiently far down in the feedtube as to come into contact with the rotating blade located in the upper portion of the working bowl.
In U.S. Pat. No. 4,226,373 a feedtube protector is provided having an outer sleeve which carries an actuator for making the machine operative only when this sleeve is properly positioned over the feedtube. The sleeve also carries a captivated, movable food pusher which is mounted for movement within the sleeve and within the passageway in the feedtube. Accordingly, the passage in the feedtube can be expanded in width to any cross-sectional area and shape which is practicable, and when the outer sleeve of the feedtube protector is properly positioned on the feedtube, the actuator extending therefrom is operatively associated with a control means in the food processor to permit operation of the motor drive.
The actuating mechanism in the aforesaid Williams patent includes a movable control rod housed in a semi-cylindrical boss on the side of the bowl. This rod is in alignment with a switch for enabling operation of the motor drive of the food processor when the switch is turned on. The outer sleeve of the feedtube protector includes an actuator which is adapted to contact the top of the control rod, thereby depressing it for turning on the switch. Thus, before the actuating mechanism in the form of the movable rod can be operated, the cover must be properly locked on the bowl in operating position with the feedtube protector positioned on the feedtube, causing the actuator to be aligned with the movable control rod for depressing the rod before the food processor can be operated.
The described expanded feedtube protector actuating apparatus in said Williams patent having multiple protective features is extremely advantageous but in some instances the present commercially available machine embodying the invention of said Williams patent may prove to be inconvenient to the user. For example, the cover is first put on the bowl and the feedtube protector is then nested on the feedtube and rotated with the cover into the locked position, so that an actuator cam on the outer sleeve of the feedtube protector depresses the control rod to enable operation of the machine. In order to reload the machine for further food processing, the feedtube protector must be rotated with the cover away from the locked position, the protector is then removed, and the feedtube is loaded, and then the protector is repositioned on the feedtube and the cover is rotated back again to its locked position for causing the actuator cam to again depress the control rod for enabling operation of the machine.